Issues with Octave:

Black window at the beginning, need to click with mouse

Bode plots are supported for SISO systems only. A splitted graphics with
a matrix of plots of all the crosswise transfer functions is not
implemented.

Use case 1, Transfer function: 

The step response of system SIMO can't plotted as the current I_OP1 has a
numerator with higher power in s than the denominator. There's a current
impulse in the step response (needed to instantaneously load the two
capacitors). Such system's can't be simulated in the time domain and thus
no step response can be plotted. This limitation is acceptable but the
feedback the user gets isn't. Octave simply says: "error: tf: tf2ss:
system must be proper" In comparison to this, MATLAB says: "Cannot
simulate the time response of LTI models with more zeros than poles." The
latter is to the point and meaningful.